Substrate Concentration Of Competitive Inhibition Of Enzyme Catalysis Calculator

Formula Used:

\[ S = \frac{V_0 \times (K_M \times (1 + \frac{I}{K_i}))}{(k_2 \times [E_0]) - V_0} \]

Initial Reaction Rate (V₀):

mol/m³·s

Michaelis Constant (K_M):

mol/m³

Inhibitor Concentration (I):

mol/m³

Enzyme Inhibitor Dissociation Constant (K_i):

mol/m³

Final Rate Constant (k₂):

1/s

Initial Enzyme Concentration ([E₀]):

mol/m³

Substrate Concentration (S):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Substrate Concentration in Competitive Inhibition?

Substrate concentration in competitive inhibition refers to the amount of substrate required to achieve a specific reaction rate when an inhibitor competes with the substrate for the enzyme's active site. Competitive inhibition occurs when an inhibitor molecule resembles the substrate and binds to the active site, preventing the actual substrate from binding.

2. How Does the Calculator Work?

The calculator uses the competitive inhibition formula:

\[ S = \frac{V_0 \times (K_M \times (1 + \frac{I}{K_i}))}{(k_2 \times [E_0]) - V_0} \]

Where:

\( S \) — Substrate Concentration (mol/m³)
\( V_0 \) — Initial Reaction Rate (mol/m³·s)
\( K_M \) — Michaelis Constant (mol/m³)
\( I \) — Inhibitor Concentration (mol/m³)
\( K_i \) — Enzyme Inhibitor Dissociation Constant (mol/m³)
\( k_2 \) — Final Rate Constant (1/s)
\( [E_0] \) — Initial Enzyme Concentration (mol/m³)

Explanation: The formula accounts for the effect of competitive inhibition on the substrate concentration required to achieve a given reaction rate, incorporating the inhibitor's affinity for the enzyme through the dissociation constant.

3. Importance of Substrate Concentration Calculation

Details: Calculating substrate concentration in competitive inhibition scenarios is crucial for understanding enzyme kinetics, designing biochemical experiments, and developing pharmaceutical drugs that target specific enzymes through competitive inhibition mechanisms.

4. Using the Calculator

Tips: Enter all values in appropriate units. Ensure that the denominator ((k₂ × [E₀]) - V₀) is positive for valid results. All concentration values must be positive, and rate constants must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is competitive inhibition?
A: Competitive inhibition occurs when an inhibitor molecule competes with the substrate for binding to the enzyme's active site, increasing the apparent K_M value without affecting V_max.

Q2: How does competitive inhibition affect enzyme kinetics?
A: Competitive inhibition increases the apparent Michaelis constant (K_M) while the maximum velocity (V_max) remains unchanged, meaning more substrate is needed to achieve the same reaction rate.

Q3: What is the significance of K_i in competitive inhibition?
A: The inhibition constant (K_i) represents the dissociation constant for the enzyme-inhibitor complex. A lower K_i value indicates stronger inhibitor binding and more effective inhibition.

Q4: Can competitive inhibition be overcome?
A: Yes, competitive inhibition can be overcome by increasing the substrate concentration, as the inhibitor and substrate compete for the same active site.

Q5: What are some examples of competitive inhibitors?
A: Common examples include statin drugs (HMG-CoA reductase inhibitors), sulfa drugs (dihydropteroate synthase inhibitors), and many antiviral drugs that compete with natural substrates.